Information storage devices are in wide spread use, and are used to store and retrieve large amounts of data. Such information storage devices generally include a rigid media for storing information, a read/write device for creating and accessing the information, and an actuator assembly for positioning the read/write device over the rigid media. One common example of such an information storage device is a hard disk drive having one or more rotating magnetic disks, over each of which a head suspension and a head slider are positioned. Each of the head suspensions are attached to the actuator assembly of the disk drive, which positions the suspensions and sliders at a desired location over the rotating disks.
An actuator assembly in a hard disk drive includes an actuator block, one or more arms extending from the actuator block, and the plurality of head suspensions discussed above, each of which is mounted to one of the arms of the actuator block. The number of arms and head suspensions in the actuator assembly is usually dependent on the number of disks in the disk drive, with a head suspension usually positioned on each side of the individual disks. Each head suspension is typically mounted to an arm of the actuator block by swaging or ball staking a vertical swage boss extending from a base plate on an end of the head suspension to the arm. In this method, the swage boss is inserted in a hole in the arm. The swage boss of the suspension is then deformed and engaged with the arm by forcing a round ball through the boss.
An alternative method for mounting a head suspension to an actuator arm is shown in the Reidenbach et al. reference, U.S. Pat. No. 4,943,875. In this reference, two flexible end portions of an actuator arm are inwardly flexed and positioned within a tube attached to a pair of blades. The flexible portions are released to engage the sides of the end portions with the inner side surfaces of the tube to secure the blades to the actuator arm. Other methods for securing blades to the actuator arm shown in the Reidenbach et al. reference include the insertion of adhesive strips in the tube, or the use of a compressible elastomeric locking member in the tube.
The head suspension mounting methods described above, however, have certain disadvantages. With respect to suspensions swaged to the actuator, increased spacing between the suspensions is typically required to accommodate the height of the vertical swage boss. In addition, a large vertical force must be used to swage the boss to the actuator arm, which can warp or otherwise permanently deform the actuator assembly. Suspensions that are swaged to the actuator block also cannot be selectively reworked or replaced because the swaging process cannot be reversed. With respect to alternative methods for attaching head suspensions, such as those shown in the Reidenbach et al. reference, these methods are often complex, and may not provide sufficient mechanical retention to correctly hold the head suspension in place as the actuator assembly quickly positions the head suspension. There is therefore a continuing need for an actuator assembly having an improved head suspension mount. Such an improved assembly should securely hold head suspensions in place as the actuator rotates, and should permit the selective rework or replacement of head suspensions. The improved assembly should also not require large vertical forces to attach suspensions to the actuator, and should be efficient to manufacture. An actuator assembly having reduced spacing between individual head suspensions would also be highly desirable.